The present disclosure relates to a drive apparatus, a drive method, and an electronic device.
In a solid state image sensor such as a CMOS image sensor, the address of pixels arranged two-dimensionally is specified for each pixel row and a signal is input into pixels in the specified pixel row to drive the pixels. Driving pixels means various operations such an accumulation operation of charges in accordance with incident light, a reset (that is, sweeping away of accumulated charges) operation of pixels, and a read operation of accumulated charges being performed by pixels by driving various transistors constituting pixels. A captured image is formed by various kinds of signal processing being performed on a signal (pixel signal) corresponding to accumulated charges read from each pixel.
In an imaging apparatus, for example, a digital still camera or the like, on the other hand, a total-pixel read mode in which a captured image is generated from pixel signals read from all pixels in the solid state image sensor and a thinning-out read mode in which a captured image is generated from pixel signals read from a row in every several rows may be switchable. By applying the thinning-out read mode, the total time to read pixel signals from a pixel array, that is, the photographing time to obtain a captured image for one frame can be reduced.
In thinning-out read mode, however, a problem of deterioration in quality of a captured image by blooming may be posed. Blooming is a phenomenon in which charges overflow from a photodiode of a pixel in a state in which charges are accumulated up to a saturation state into neighboring pixels after light is further incident thereon. The inflow of charges into neighboring pixels could cause quality deterioration such as color mixing. In thinning-out read mode, thinned-out pixels are maintained in a state in which charges are accumulated without being read during exposure time and are likely to cause blooming.
Various measures are taken against deterioration in quality caused by blooming. According to the technology described in JP 2008-288904A, for example, a sweeping operation of extra charges from pixels to be thinned out (hereinafter, referred to as an electronic shutter operation) and a read operation of pixel signals from other pixels (hereinafter, referred to simply as a read operation) are both performed within a horizontal scanning period (1H period) as a time necessary to scan pixels of one row when a photograph is taken in thinned-out read mode to prevent the occurrence of blooming JP 2008-288904A discloses a technology that prevents the occurrence of blooming caused by thinned-out pixels and also reduces the blanking period in which no pixel signal can be read out by providing an address selection circuit combining an address decoder and a 2-bit memory in each row of a pixel array and making a selection of the address of the pixel row in which the electronic shutter operation is performed and a selection of the pixel row in which the read operation is performed by the address selection circuit. JP 2008-288903A discloses a concrete control method of the address selection circuit described in JP 2008-288904A.